How To Measure Roof

First thanks for the input about my home equity inquiry.

My first improvement will be a new roof. I want to be sure I'm not paying for more bundles of shingles than I will actually need.

So, how do I measure my roof to determine how many bundles will be needed?

My house is a conventional rectangular ranch (30'x60') and has a

10'x12' utility room attached on the end of back of house, giving it an L shape

Both are conventional A-roof construction and the utility room is tied to the main part of house (roof).

Also, I've heard differing opinions as to whether or not to have old shingles removed vs just layering the new roof over the old. Does it matter? Or is it safe and efficient to put new over old?

Thanks very much.

V_V

Reply to
Virtual.Voyager
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Do your best guess on number of bundles. The store from which you buy them will almost certainly take back unopened bundles (or sell you some more if you underestimate). Of course you should verify that policy first, but any reputable supplier should be more than happy to accommodate you.

Tearing off is always best - for several reasons.

  1. It gives you an opportunity to inspect, and repair if necessary, areas not otherwise visible.
  2. It decreases the weight on the roof and, to some degree, the heat buildup on the new shingles.
  3. It's easier to do a good job on flashings, vents, and gutters.

The downside is, of course, the cost. There's a lot of labor involved in removing the old shingles and usually some charge to haul off and dispose of the junk.

Reply to
HeyBub

Reply to
Steve Barker DLT

Need to know the pitch. Then it's simple math and geometry.

s

Reply to
Steve Barker DLT

... or you can just measure the surface of the roof.

Reply to
gfretwell

Remember the geometry story problems from junior high school? This is one of those. From the ground-level dimensions, and the approximate angles of the gable ends (the 'a-frames'), you should be able to get a pretty close square footage of the shingle area. (hint- a2+b2=c2 will give you the dimensions of half of each gable.) Take that plus a 10 % fudge factor for wastage, and you should know how many bundles of shingles (3 bundles per 100 sq. feet) you will need. There is also the cost of flashing, ice dam, misc special materials, and so forth. Don't sweat the exact bundle count- they are cheap, and it is only a tiny fraction of the installed price. And make sure they leave at least the last partial bundle behind, and stash it away someplace cool and dry, for any future repair work.

As to tear-off vs. overlay? IMHO, which is largely supported by most regular posters on here, tear-off and start from bare wood is the best way to go. It allows you to inspect the deck and flashing and repair any bad spots, and makes the new roof look better and last longer. It is also a lot lighter in weight, which makes a difference in snow country. It does cost a few hundred more, and adds a day or two to the job, but considered against the several thousand the work will cost, it is cheap insurance.

Most roofing companies offer free estimates. Call 3 or 4 out for a site visit. Throw out any that try to hard-sell you T-lock overlay shingles or have a slick salesman with fancy brochures- the good ones will send an actual roofer. Specify the same shingles with each company, typically

25-year 'architectural' (aka textured) shingles are the current standard. Specify ice dam membrane in the valleys and along the eaves, and refresh of any damaged deck and flashing. Make sure they all quote the same vent system, usually ridge vent these days, but at least new metal vents if that is what is up there. (If more vents are needed, this is the best time to add them.) The top companies in your area will likely be within a few hundred dollars of each other. All the usual caveats about making sure the company is licensed, bonded, and has workmans comp apply- a quality company will have all that info available, and not be offended if you ask. (All mine included copies with their bids as a matter of course.) Avoid any companies that the guy runs out of his truck- drive by their office/yard, and see if they keep it clean and in good condition. Doesn't have to be a fancy building, and the trucks don't have to be new and shiny, but hillbilly is as hillbilly does, and I've found that subs who can't even keep their own operation looking neat and workmanlike don't do any better on the jobsite. Plus of course the usual- ask for addresses of previous jobs they did, like 2-3 years ago, and drive by and see how they look from the street.

I did all the above, and ended up going with a ma-and-pa outfit just down the road. They beat the slick places by several hundred dollars, and they were in and out in 5 days, and cleaned up after themselves.

-- aem sends...

Reply to
aemeijers

Many thanks again to all.

As to the venting, currently the only vents are the louvered vents in the ends of the gable(?) ends. I was thinking about having two air turbin vents installed. The attic is very well insulated and it is VERY hot in the attic during the summer here in VA.

Are these vents efficient? If so yes and I have them installed do they need to be covered in the winter months?

I appreciate everyone's patience, time and efforts answering my questions.

V_V

Reply to
Virtual.Voyager

You've got stacks for sewers, exhausts for (gas) water heaters and furnaces.

Turbine vents are very efficient inasmuch as their energy consumption is zero! They convert mechanical energy (wind) into suction. But they don't work worth beans when there's no wind. For that reason, also add ridge vents.

In other words, when you re-do your roof, add ridge vents AND turbines. This brings up another point:

You can't have too much soffit vents. Whatever you've got, double it. You can find calculations for the total necessary soffit venting on the web.

And, no, you don't cover them in the winter. Maintaining circulation in the attic, even when cold, is appropriate to prevent condensation and and attendant rot.

Reply to
HeyBub

You have good answer to your questions.

Are you planning to do the work yourself?

If so, and you haven't done it before, read the bundle and follow those instructions. There is nothing requiring a rocket scientist to roofing but it has to be done right. The bundle will give the correct 'how to'.

One point if you are doing it yourself. Please, please, do not run it so the cutouts (if those are the type shingles you use) line up vertically running up the roof. That is a sure sign that an amateur did the work. Stagger the joints as thebundles will show. You wind up with a far, far better looking roof and errors in lineup pretty well just disappear.

Also, again if you are doing it, purchas a shingle hatchet. It spaces the shingles for you and saves and immense amoutn of time. Took me 2 jobs before I got one for the third and kicked myself for not doing it on the first one.

Harry K

Reply to
Harry K

want to try something different, perhaps you could take photos of the various roof surfaces with both a vertical and horizontal rules in the photo. Then you can use the photo to figure out the area.

Another way is to use google map satellite view, but you'd need to obtain the roof pitch some other way

Reply to
john

Put a metal roof over it and be done with it.

Reply to
Blattus Slafaly

Gosh no! You never seal off an attic; winter or summer. It must remain ventilated to avoid condensation, mould and rot. The absolute minimum venting (here anyway) IIRC is around 3 square feet per 1000 sq feet of attic 'floor area'. BUT it must be distributed so that there is cross- ventilation. You insulate your house ceilings and you can't have too much attic venting.

Reply to
terry

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